/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.hddz.comlib.ui.base.quicksearchbox;

import java.util.ArrayList;

import android.database.DataSetObservable;
import android.database.DataSetObserver;

/**
 * A SuggestionCursor that is backed by a list of SuggestionPosition objects.
 * This cursor does not own the SuggestionCursors that the SuggestionPosition
 * objects refer to.
 * 
 */
public class ListSuggestionCursor extends AbstractSuggestionCursorWrapper
{
	private final DataSetObservable				mDataSetObservable	= new DataSetObservable();
	private final ArrayList<SuggestionPosition>	mSuggestions;
	private int									mPos;

	public ListSuggestionCursor(String userQuery)
	{
		super(userQuery);
		mSuggestions = new ArrayList<SuggestionPosition>();
		mPos = 0;
	}

	/**
	 * Adds a suggestion from another suggestion cursor.
	 * 
	 * @param suggestionPos
	 * @return {@code true} if the suggestion was added.
	 */
	public boolean add(SuggestionPosition suggestionPos)
	{
		mSuggestions.add(suggestionPos);
		return true;
	}

	public void close()
	{
		mSuggestions.clear();
	}

	public int getPosition()
	{
		return mPos;
	}

	public void moveTo(int pos)
	{
		mPos = pos;
	}

	public boolean moveToNext()
	{
		int size = mSuggestions.size();
		if (mPos >= size)
		{
			// Already past the end
			return false;
		}
		mPos++;
		return mPos < size;
	}

	public void removeRow()
	{
		mSuggestions.remove(mPos);
	}

	public void replaceRow(SuggestionPosition suggestionPos)
	{
		mSuggestions.set(mPos, suggestionPos);
	}

	public int getCount()
	{
		return mSuggestions.size();
	}

	@Override
	protected SuggestionCursor current()
	{
		return mSuggestions.get(mPos).current();
	}

	@Override
	public String toString()
	{
		return "[" + getUserQuery() + "] " + mSuggestions;
	}

	/**
	 * Register an observer that is called when changes happen to this data set.
	 * 
	 * @param observer
	 *            gets notified when the data set changes.
	 */
	public void registerDataSetObserver(DataSetObserver observer)
	{
		mDataSetObservable.registerObserver(observer);
	}

	/**
	 * Unregister an observer that has previously been registered with
	 * {@link #registerDataSetObserver(DataSetObserver)}
	 * 
	 * @param observer
	 *            the observer to unregister.
	 */
	public void unregisterDataSetObserver(DataSetObserver observer)
	{
		mDataSetObservable.unregisterObserver(observer);
	}

	protected void notifyDataSetChanged()
	{
		mDataSetObservable.notifyChanged();
	}
}
